226
Participants
Start Date
September 30, 2011
Primary Completion Date
December 31, 2011
Study Completion Date
September 30, 2012
Control
Receive weekly emails asking participants about their exercise and receive cash.
Suggested Tying Intervention
Participants receive 4 iTunes audio novels for their own iPods to listen to only at the gym
Forced Tying Intervention
Participants receive cash and also 4 iTunes audio novels for a loaned iPod accessible only at the gym to listen to only at the gym.
University of Pennsylvania, Philadelphia
University of Pennsylvania
OTHER